Expansible cover



R. c. PIERCE 2,041,950

EXPANSIBLE COVER Filed Aug. 5, v1955 2 Sheets-Sheet 1 May 26, 1936.v

INVENTOR, ROBERT C? P/E Rcs 7h *main ATTORNEY.

Fha-. I

26, 1936 R. c. PIERCE EXPANSIBLE COVER Filed Aug.'v 5, 1955 2 Sheets-Sheet 2 INVENTQR. ROBERT C MERCE LA l F7612' ATTORNEY.

Patented vMay 26, 1933 2,04IL950v osier:

` EANSIBLE CUVE,

poration ci Michigan Application August 5. 1335, Seriai No. 34,672

2 Cla.

This invention relates to expans'ible tubular covers, and has for an object the construction of such a cover in a manner making it extremely strong while at the same time the resistance to expansion is minimized. I attain great strength by making the cover of wire braids, each consisting of wiresfextending the full length of the braid and which are braided together to form a at tape of extremely great strength. The braids are connected to endmembers such as rigid end rings, and in order to insure a minimum of friction as they slide over each other in expanding the cover, they are so laid that each one goes alternately over and under three or more of the others. I prefer to have each one go alternately over and under four of the others, this arrangement being readily laid either by hand or by machina, and giving relatively long sections of braid sliding quite freely over or under,

' as the case may be, the four other braids.

The above and other objects and features of the invention, including various novel features of construction and arrangement, will be apparl ent from the following description of the illusi trative embodiments shown inthe accompany- Figures 1, 2, and 3, but show a diierent braid` arrangement;

Figure 'l is a plan view of a section of the braid; and

Figure 8 is a section through the braid.

Both forms of covers comprise broadly end members such as rigid metal rings i connected by a series of wire braids I2. As appears in detail in Figures 7 and 8, each of the braids i2 comprises wires lll, each of which extends the full length of the braid, so that the braid has the.

cumulative tensile strength of all the wires.

The Wires are formedv into a at braid, as illustrated, and each braid is so arranged that it extends spirally about the cover, and is attached to the rings l0. They are shownv welded or otherwise permanently secured to the lower ring I0, and as extending through slots in the upper ring and either secured thereto, or carried back down the other side of the cover so that both ends of each braid are secured to the lower ring and the center is secured to the upper ring by passing through the slot.

Figures 1, 2, and 3 show one arrangement of the braids, and Figures 4, 5, and 6 show a somewhat diierent arrangement, but in both each 5 braid goes alternately over and under at least three,l and preferably four, of the others. In the drawings each braid is shown going alternately over and under four of the others.

In'Figures 1, 2, and 3, the arrangement is such that the zones of braid sections on the exterior of the cover runcircumferentiallyl around the cover; in Figures 4, 5, and 6 these zones run lengthwise of the cover. The details of the braid arrangement in both cases are shown in Figures 3 and 6. y

In both cases, in expanding the covers from theform shown in Figures l and 4 to that of Figures 2 and 5, an operation which also shortens the covers lengthwise as shown, the sections of braid which-lie either over or under the intervening braids are long enough to slide freely, thus minimizing the resistance of the cover to expansion.

One use of the expanding coveris in coal mining or the like to replace the use of dynamite in blowing down the coal. The face of coal is undercut in the usual manner and a series of holes K are drilled across the top of the face of a size to receive closely the covers in their contracted 30 condition as shown in Figures l and 4. Covers are inserted in these holes with an expansible rubber bladder or the like in each -cover and when the bladders are inflated the covers will expand as in Figures 2 and 5 increasing their diameters from two to two and one-half times and forcing the coal down. As the covers expand no interstices of appreciable size are opened up between the braids, and the bladders will be fully protected at all times. v

While two Aillustrative embodiments have been described in detail, it is not my intention to limit the scope of my invention to those particular embodiments, or otherwise than by the terms of the appended claims. l

I claim:

1. An expansible tubular metallic cover having rigid rings at its ends connected by a series oi.' wire braids, each braid being connected to said rings at the ends of the cover and each consisting of wires extending the full length of thebraid and braided together to, form a at braid extending spirally about the cover, said braids being laid so that each of them goes alternately under and over at least three of the others whereby said cover expands readily when pressure is applied thereto internally.

2. An expansible tubular metallic cover having rigid rings at its ends connected by a series of wire braids, each braid being connected to said rings at the ends of the cover and each consisting of wires extending the full length of the braid and braided together to form a at braid extending spirally about the cover, said braids being laid so that each of them goes alternately under and over four of the others wherebysaid cover expands readily when pressure is applied 5 thereto internally.

ROBERT C. PIERCE. 

